This application relates to and incorporates herein by reference Japanese Patent Application No. 11-306943 filed Oct. 28, 1999.
The present invention relates to an accessory device driving apparatus for vehicles that is disposed between an internal combustion engine and an accessory device to be driven by the internal combustion engine.
JP-A-10-336804 proposes one type of accessory device driving apparatuses for vehicles. This driving apparatus is constructed as an accessory device driving motor that is a rotary electric machine, that is, a motor/generator unit for starting an internal combustion engine of a vehicle and generating electric power. The driving apparatus has a clutch mechanism between the engine and the generator/motor unit to continue to drive the accessory device of the vehicle during the engine is held at rest for a moment (idle-stop), for instance, at intersections. Specifically, in this instance, the clutch mechanism operates to disengage the generator/motor unit from the engine so that the generator/motor unit drives the accessory device. The clutch mechanism, which generally comprises a pair of friction-type rotary disks and a disk driving device, is required to be simple in construction and durable for a long period of use.
It is therefore an object of the present invention to provide an accessory device driving apparatus for vehicles that meets required demands, such as simple construction and long durability.
According to the present invention, an accessory device driving apparatus for a vehicle is constructed as a coaxial dual rotor-type motor/generator. A first rotor is rotatably supported in a housing and coupled with an engine in a torque transfer manner therebetween, and a second rotor is rotatably supported in the housing and coupled with an accessory device in a torque transfer manner therebetween. One of the rotors is connected to a battery in an electric power transfer manner and positioned to face another of the rotors in an electromagnetically induction-coupled manner and in a relatively rotatable manner. For the electromagnetic induction coupling between the rotors, one rotor is an armature-type having armature coils and the other rotor is a rotating magnetic field generating-type. The rotating magnetic field may be provided by the use of permanent magnets or field coils.